| ABCL/c+ | ⊕ 1988 | ↓ ↑ ⊕ Experimental and other | ⊕ CPL, BCPL and B | ⊕ Japan | Concurrent actor language based on C |
| ABCL/R | ⊕ 1988 | ↓ ↑ ⊕ Experimental and other | ⊕ Actor | ⊕ Japan | Object-Based Concurrent Language |
| Alltalk | ⊕ 1988 | ↓ ↑ ⊕ Experimental and other | ⊕ United States | Smalltalk with persistency | |
| ARTS/C | ⊕ 1988 | ↓ ↑ ⊕ Experimental and other | ⊕ CPL, BCPL and B | ⊕ Japan | |
| CST | ⊕ 1988 | ↓ ↑ ⊕ Experimental and other | ⊕ United States | Concurrent OO Language | |
| GARP | ⊕ 1988 | ↓ ↑ ⊕ Experimental and other | ⊕ Graph | ⊕ United States | Graph-based hybrid concurrent OO language |
| Hope+ | ⊕ 1988 | ↓ ↑ ⊕ Experimental and other | ⊕ United Kingdom | ||
| Seque | ⊕ 1988 | ↓ ↑ ⊕ Experimental and other | ⊕ United States | Experimental language for manipulating sequences | |
| Trilogy II | ⊕ 1988 | ↓ ↑ ⊕ Experimental and other | ⊕ Canada | ||
| W2 | ⊕ 1988 | ↓ ↑ ⊕ Experimental and other | ⊕ Pascals | ⊕ United States | Systolic array parallel language |